Analysis of residual phases in nickel aluminide powders produced by reaction synthesis

摘要

The use of x-ray diffraction has been used to determine phases present after reaction synthesis of Ni(sub 3)Al powder. The complex diffraction spectra produced by the powder prompted the development of a simulator. The simlulator uses nonlinear regression to determine the weight percent of the phases present. The simulator also determines the broadening of each peak in the spectrum. The phases present in Ni(sub 3)Al powder produced by reaction synthesis has been determined with the simulator. The simulator has been used to monitor the progress of phase transformation during various thermal treatments of Ni(sub 3)Al powder. A thermal cycle of 1200(degrees)C for two hours has been shown to produce a phase-pure product. The activation energy for the interdiffusion of nickel and aluminum has been determined to be 260(plus minus)35 kJ/mole.